Press jaw system



- H G. SWEDE PRESS JAW SYSTEM Nov. 12, 19568 2 Sheets-Sheet 1 FiledApril 8. 1966 INVENTOR HA R A L D G. SWEDE BY MRM ATTORNEY Nov. 12, 1968H. G. SWEDE PRESS JAW SYSTEM 2 Sheets-Sheet 2 Filed April 8. 1966 Fig. 2

INVENTOR HARA-LD e. sweog M M n ATTORNEY United States Patent PRESS JAWSYSTEM Harald Georg Swede, Malmo, Sweden, assignor to AB Tetra Pak,Lund, Sweden, a Swedish company Filed Apr. 8, 1966, Ser. No. 541,256Claims priority, application Sweden, May 6, 1965,

4 Claims. (Cl. 100-264) ABSTRACT OF THE DISCLOSURE Apparatus to seal offa tube by pressing the tube closed between a set of jaws which are somounted as to take advantage of the reaction forces in the system. Alinkage system is used to simultaneously exert force on both jaws tobring them together by pushing on one jaw and pulling on the other jawsimultaneously.

The present invention refers to a press jaw system, including two pressjaws which are adapted to press a pressing material between them, andpreferably intended to be applied to machines having press jaws movablein pairs for working upon a movable web of material or similar pressingmaterial, said system being characterized by the fact that the pressjaws are associated with pulling means which are arranged to beconnected together and to provide the necessary pressing force bydrawing the press jaws toward each other, the pressing force exerted bythe jaws being wholly or partially compensated internally of the systemby a corresponding pulling force in said pulling means.

For example, the system according to the invention may be used for pressjaws which are utilized for fiat pressing and transverse sealing of atube to form filled, sealed packages. More particularly in devices ofthis kind and similar devices which operate with jaws movable along ortogether with a web of material, problems often arise by large reactionforces having to be taken up, for example by the machine frame. In thesystem according to the present invention, on the other hand, it is madepossible for these reaction forces to be wholly or partially compensatedinternally in direct connection with the press jaws.

The invention will be described more closely in the following withreference to the accompanying drawings, which by way of example show apreferred embodiment of the invention, FIGURE 1 showing a lateral viewof one press jaw belonging to the system, together with a link systemwhich is intended for providing the movement of the jaw, and a detail ofthe other press jaw, while FIGURE 2 shows the right hand side of thefirst-memtioned jaw, as seen from the line AA in FIGURE 1.

The system shown as an example includes two press jaws 1 and 2, the jaw1 being mounted on a turning arm 3 which is mounted rotatable around apivot shaft 4. On the turning arm 3, with the shaft 4 as a centre, thereis further provided a toothed segment 5, which in FIGURE 1 has beenshown diagrammatically by drawing the pitch lcircle thereof as a dashand dot line. Also the jaw 2 is mounted on a corresponding turning arm(not shown) connected to jaw 2 and having a corresponding toothedsegment 5A which is in engagement with the segment 5. In FIGURE 1,however, these details have been omitted for simplicity.

3,410,201 Patented Nov. 12, 1968 In the upper part of the turning arm 3an eccentric axle 6 is rotably mounted in a bearing 7. This eccentricaxle 6 at each end carries an eccentric pin 8 and a second eccentricallydisposed pin 9, the pin 9 being intended to serve as a mover pin formoving a locking detent 10 mounted on the pin 9 against the action of aspring not shown at the rotation of the eccentric shaft 6 by means of alink 11. At one end this link 11 is rotatbly mounted on the eccentricpin 8, while its other end is arranged to carry out a movement which ispositively controlled by a link and sliding arm system.

Said link and sliding arm system includes a three point link 12 which atone point B is rotatably connected with said other end of the link 11.With a second point C as the centre a guiding disk 16 is arranged on ashaft 13. This guiding disk 16 is mounted stationary in relation to thepivot shaft 4 of the turning arm 3. At a third point D on the threepoint link 12 the force which is to be transmitted to the turning arms 3and the jaws 1 and 2 is applied. For example, this force may be carriedto the point D by means of a Bowden-cable or similar element whichshould be able to transmit both pulling and pushing forces. How thistakes place is of minor importance to the invention. For this reasonthis power transmission element has been omitted in the drawings. It isessential, however, that the point D is caused to perform a positivelycontrolled movement, which in the example shown takes place by means ofa rectlinear guide from D to D. Here the point C moves along the groove15 in the guiding disk 16 to a position designated by C. Hence, also thepoint B moves positively controlled from B till B along the curved line17. At this movement the jaw 1 on the turning arm 3 is turned to theposition designated by 1', at the same time as the eccentric axle 6 isrotated. This causes the eccentric line E-F to be moved first to theposition designated by F'E" and then rotated with the rotation centre Eof the eccentric axle 6 to the position FE'.

While the centre of the eccentric axle 6 is moved from E to E" and thejaw 1 is moved to the position designated by 1', the mover pin 9,against the action of a spring not shown, causes the detent 10 to beturned down to the position designated by 10 so as thereupon to becaused to engage a second detent 18 rigidly connected with the jaw 2.When finally the eccentric line FE" is turned to the position F' apulling force is obtained in the detents 10 and 18, which causes acorresponding pressing force between the jaws 1 and 2. It should beclear now that as link 12 moves upwardly to position C the arm 3 withthe sealing means 1 is swung in a clockwise direction and EF will bemoved to the position F'E". Then, when the link 12 moves to the nextposition C the arm 3 will remain in an unchanged position but the detent10 will continue to rotate and engage the detent 18 since the line E-Fhas now moved to the position F'E'. When the detent 10 engages thedetent 18 it will exert a force on the jaw 2 towards the jaw 1 bringingthem tightly together thereby exerting both a pulling force and apushing force on the jaw 2. It can be seen also that when jaw 2 ispulled towards the jaw 1 that jaw 1 will be moved towards jaw 2 throughthe co-action of the toothed gears 5 and 5A. These forces then form asubstantially closed system of forces, whereby reaction forces acting onthe other parts of the machine are substantially reduced as comparedwith the corresponding prior systems.

In FIGURE 1 the positions of the points B, C and D corresponding to Fhave been indicated, which have been designated by B", C and D",respectively.

As will be understood, the invention is not limited to the exampledescribed above alone, but may be varied within the scope of thefollowing claims.

Thus, for example, the movement of the point B to B may be provided inmany ways. One possibility is to have the link 11 guided direct by a camguide of the desired shape. The individual detailed constructions willmoreover be very much dependent on the actual design of the machine towhich the invention is to be applied. In certain cases it may then besuitable to guide each jaw Separately, the system described abovegenerally being duplicated.

That which is claimed is:

1. A press jaw system comprising: a set of press jaws, means tosynchronize the movement of one jaw to bring it into pressing relationwith the other of said jaws and means to pull said jaws towards oneanother by exerting a pulling force on one of said jaws.

2. The structure of claim 1 wherein the means to pull said jaws togetherincludes detents on each of said jaws with the detent on one jawengaging the detent on the other jaw to pull the jaws into engagement.

3. The structure of claim 2 wherein one of said jaws is mounted on aturning arm, a shaft rotably mounted in said turning arm, a pineccentrically mounted on said shaft, said detent pulling said jawstogether being opera bly associated with eccentrically mounted pin.

4. The structure of claim 3 wherein said shaft is eccentrically mountedwith respect to said turning arm.

References Cited UNITED STATES PATENTS 2,509,516 5/ 1950 Murphy 100-278XR 2,63 7,268 5/ 1953 Culver 100 278 XR BILLY I. WILHITE, PrimaryExaminer.

